Method of intermixing a plurality of liquids of different specific gravities



Aprll 19, 1960 A. FERRARI, JR 2,933,293

METHOD OF INTERMIXING A PLURALITY 0F LIQUIDS OF DIFFERENT SPECIFIC GRAVITIES Filed Sept. 12, 1956 F'GJ Processing 4 i l M:

i Recorder H Caiarz'mefer I Med/um f- (EL ATTORNEYS United States Patent METHOD OF INTERMIXING A PLURALITY OF LIQUIDS OF DIFFERENT SPECIFIC GRAVITIES Andres Ferrari, Jr., Scarsdale, N.Y., assignor, by mesne assignments, to Technicon Instruments Corporation, Chauncey, N.Y., a corporation of New York Application September 12, 1956, Serial No. 609,366

3 Claims. (Cl. 259-4) The present invention relates to liquid mixing apparatus, and while useful for other purposes is especially valuable for thoroughly mixing blood or other body fluids with a processing liquid in apparatus utilized for analyzing body fluids in respect to critical constituents thereof for diagnostic purposes.

The present invention has been developed for use in the body fluid analyzer apparatus disclosed in the patent of Leonard T. Skeggs, No. 2,797,149, filed January 8, 1953, issued June 25, 1957, and assigned to the owner of present invention and application. Accordingly, the mixing device disclosed herein is illustrated in connection with such apparatus as an element thereof.

Briefly described, in the above mentioned body fluid analyzing apparatus, blood or other body fluid together with one or more primary processing fluids is caused to pass to one side of a dialyzer, and one or more secondary processing fluids are caused to pass to the other side of the dialyzer, resulting in the separation from the body fluid of the crystaloid constituents thereof, the protein or other non-crystaloid constituents being exhausted from the first mentioned side of the dialyzer. The process is a continuous flow process for each sample of fluid, and a series of samples are automatically transmitted seriatim through the apparatus, as more fully described in the above identified Skeggs application and in the application of Leonard T. Skeggs, Serial No. 547,087, filed November 16, 1955, also assigned to the owner of the present application.

The primary object of the present invention is to provide a mixing device which is well adapted to effect a thorough mixing of the body fluid and the primary processing fluid or fluids during the flow of said fluids to the dialyzer.

Another object is to provide a mixing device which requires no moving parts and which is effective automatically, merely as a result of the fluid flow therethrough and without stirrers or other agitation means, to accomplish the thorough mixing of the fluids passing therethrough.

The above and other objects, features and advantages of this invention will be fully understood from the following description considered in connection with the accompanying illustrative drawings, the presently preferred embodiment of the invention being thereby described and illustrated.

In the drawings:

Fig. 1 is a more or less schematic view of body fluid analyzing apparatus provided with the liquid mixing device of the present invention;

Fig. 2 is a sectional view, on an enlarged scale, of part of the mixing device;

Fig. 3 is a sectional view of part of one of the convolutions of the mixing device, illustrating a partial mixing or blending of the liquids; and

Fig. 4 is a sectional view on the line 4-4 of Fig. 1 illustrating the complete inter-mixture or blending of the fluids by the mixing device before leaving the latter.

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Referring now to the drawings in detail and first to' Fig. 1, the mixing device 10 embodying the present invention comprises a helical coil of tubing formed of glass or other suitable material inert to the liquids and fluids passing therethrough and preferably transparent or translucent, at least in part, so that the fluid flow therethrough can be observed. A proportioning pump 12 of any suitable type is provided for pumping the blood or other body fluid samples and the processing liquid or liquids and also preferably air, in accordance with the Skeggs processes as described in his above mentioned applications, to the inlet end portion 14 of coil 10 or to a tube connected thereto. The inlet for the body fluid sample and for said other fluids are indicated by the legends in Fig. 1. The outlet 16 of the coil 10 is disposed in a fluid flow circuit leading to the dialyzer 18 either through a heater 20 when the use of the latter is necessary in accordance with the particular process employed or directly by means of the tube 22. Valves 24 and 26 are provided in the fluid line for controlling the flow to the dialyzer either directly thereto from the outlet of the mixing coil or indirectly through the heater 20 in a manner which is obvious and which is also described in the above mentioned Skeggs applications.

The other fluids employed in the process are pumped simultaneously with the above mentioned fluids and in quantities proportionate to the latter to the dialyzer by means of the tube 28, in the case of certain of the fluids, as indicated by the legends, and to a color development chamber 30 by means of the tube 32 in the case of the liquid designated reagent which is efiective to produce a color change in the liquid which flows to chamber 30 through tube 34 connected to the side of the dialyzer which contains the separated crystaloid constituent of the body fluid. In certain processesheat is utilized instead of a reagent for developing the color characteristic in the crystaloid containing liquid. Accordingly, the apparatus illustrated in Fig. 1 is provided with a heater 36 the inlet of which is controlled by a valve 38 which is operated to place the outlet tube 42 of the dialyzer in communication alternatively either with tube 34 which leads to mixing chamber 30 or to heater 36. A cooling coil 40 is shown interposed in the conduit 42 leading from the heater 36 to the supply tube 44 which conducts the fluids through the colorimeter 46 which controls the operation of a recorder 48, as described in the Skeggs applications.

The manner in which coil 10 acts to thoroughly mix the liquids automatically as they flow therethrough is believed to be obvious from the description and the illustrations afforded of Figs. 2, 3 and 4 of the drawings. Thus, referring to Fig. 2, it will be observed that the blood indicated at B in Fig. 2 of the sample to be analyzed joins with the processing liquid indicated at P, and since the blood has a higher specific gravity than the processing liquid the two liquids tend to stratify in the conducting tube 14. The air which enters said tube divides the stream of blood and processing liquid into a plurality of air-spaced segments indicated at S1, S2, S3, and so on, as the stream continues to flow to and through the several convo'lutions mixing coil. As the stream of liquid segments flows through the several convolutions of the coil, the blood and the processing liquid intermingle, a partial intermingling or mixing being indicated in Fig. 3 and a complete intermingling and thorough mixing of the blood and processing liquid being illustrated by Fig. 4. It will be observed that as the fluids pass through the coil they move in a path which is such that they tend to mix with each other and, moreover, when as in the case of blood which is heavier than the processing fluid and is supplied so that it flows initially along the outer marginal circular portion. of the convolutions, the heavier fluid mo'ves by gravity toward and into the lighter fluid which flows along with said heavier fluid in coil 10.

It may be noted that this intermingling and thorough mixing of the blood and processing liquiddoes not depend upon the admission of the air into the stream, the latter being illustrated because or",the preference. for its use in the process as described in the Skeggs applications,

' Thus it is seen that the mixing device described desire to secure by Letters Patent, is;

l. The method of intermixing a plurality of liquids of different specific gravities, respectively, comprising fo'rming a flowing stream containing said plurality of liquids, causing said stream to flow alternately and successively upwardly and downwardly in a continuous path from a lower part of said path to an upper part thereof and from said upper part thereof to a lower part thereof and .in such direction that portions of the liquids flow first below other portions of the liquids, whileflowing in the lower parts ofsa 'd path, andabove said other portions or" the liquids, while flowing in the upper partsof said path, whereby saidportions of the liquids are repeatedly mixed during the flow thereof, and introducting an inert gas into said stream and thereby subdividing said stream into successive segments of liquids separated by intervenin se men of a so h the mix n f. the qu s ing the flowthereof takes place in each liquid segment.

2. The method of intermixing a plurality of liquids of diiferent specific gravities, respectively, comprising forming a flowing stream containing said plurality of liquids wherein said liquids of difierent specific gravities are in different vertical positions in saidflowing stream, causing said stream to flow alternately and successively upwardly and downwardly in a continuous curved path from a position in the lower part of said path to a position in the upper part thereof and from said upper part thereof to a position in a lower-part thereof 'and'in'such direction to cause portions of theliquids to'change their vertical-position and moveinto other portions of the liquids, while flowing in the lower part of said path and to again change page 685, Fig. 1.

their vertical positions and move into said other portions of the liquids while flowing in the upper parts of said path, whereby said liquids are repeatedly mixed during the How thereof, and introducing air into said stream and thereby subdividing said stream into successive segments of liquids separated by intervening segments of air so that the mixing of the liquids during the flow thereof takes place in each liquid segment. s

3. The method of intermixing a plurality of liquids of difierent specific gravities, respectively, comprising forming a flowing stream'containin g said plurality of liquids in a Stratified condition wherein said liquids of higher specific gravities are in the lower layers of said flowing stream and said liquids of lower specific gravities are in the upper layers of said flowing stream, causing said stream to flow alternately and successively upwardly and downwardly in a continuous vertical helical path from a position in the lower part of said path to a position in the upper part thereof and from said upper part thereof to a position in the lower part thereof and in such direction to cause portions of said liquids of higher specific gravities in the lower layers of said stream, when in said lower part of said path, to move into portions of said liquids of lower specific gravities in the lower layers of said stream when said stream is in the upper part of said path and to move into portions of said liquids of lower specific gravities inthe lo'wer layers of said stream when said stream flows from said upper part of said path to said lower part thereof, whereby said liquids are repeatedly mixed during the flow thereof, and introducin'g air into said stream and thereby subdividing said stream into successive segmerits of'liquids separated by intervening segments of air so that the mixing of the liquids during the flow thereof takes place in each liquid segment.

References Cited in the file of this patent UNITED STATES PATENTS 2,000,953 Hooker et al. May 14,1935 2,230,255 Laumiet et al. Feb. 4, 1941 2,263,118 Carney Nov. 18, 1941 2,516,884 Kyame Aug. 1, 1950 2,784,948 Pahl et al. Mar. 12, 1957' 2,797,149 Skeggs June 25, 1957 OTHER REFERENCES Surgery, Gynecology and Obstetrics, Dec. '19, 1:949,

Surgery, vol. "l0,'l lumber {page 365, July-1 956. 

